On Aquatic Carnworous Coleoptera or Dytiscide. 641 
rounded ; the prosternal process is slightly shorter and broader. It would thus 
appear that this female in structure a good deal resembles D. pisanus, with an 
approximation towards D. marginalis, and with the punctuation almost similar to 
(the smooth female of) that species. 
Persia; found (I believe at Ispahan) by the Marquis Jacques Doria in 1862 or 63. 943. 
994, Dytiscus marginalis, Linn., M.C.—Subtus testaceus, metasterno in medio 
nigricante, supra nigro-olivaceus, prothorace limbo omni elytrisque lateribus flavo- 
marginatis, antennis pedibusque rufis, tarsis posterioribus plus minusve picescenti- 
bus; prosterni processu lato, haud elongato, coxarum processubus brevibus, sat 
acuminatis, Long. 33, lat. 18 m.m. (Long. 26-34 m.m.) 
Mas, nitidus, elytris ad apicem sat punctatis. 
Fem. (a), subopaca, elytris ad basin ultra medium suleatis, ad apicem crebrius 
et fortius punctatis, prothorace undique crebrius parum subtiliter punctato. 
(b), nitida, prothorace subopaco, undique subtiliter punctulato, elytris apicem 
versus crebrius quam in mare punctatis. 
The male has the small palettes on the front feet large and highly developed, those 
near the two large cups being especially large and distinct, those on the middle feet 
are very small, but still are to be distinctly distinguished. The species varies a 
good deal in size, the females being particularly liable to reduction in this respect, 
and it also varies in the colour of the undersurtace, the ventral segments being 
occasionally much marked with black. Except for these points and the sexual 
discrepancies, the species shows but little variation; the individual from Japan 
is, however, a very broad one, and appears to me to have the small cups of the front 
male tarsi rather less developed than in the European specimens. 
This species is comparatively widely distributed in Europe, it occurs within the 
Arctic circle, (68°, Sahlberg), and as far south as Geneva, Lombardy, and Trente, 
and Hautes Pyrenees. It has not been recognized as occurring in America, but I 
have a female individual labelled, ““Am. bor.int., montagnes rocheuses,” by Castlenau; 
and found an individual said to be from North America, in Murray’s collection. 
Europe, Stheria, Japan, North America. 944. 
Group 2. 
995. Dytiscus cireumcinctus, Ahr., M.C.—Subtus testaceus vel ferrugineus, 
metasterno in medio obscuro, supra nigricans, prothorace limbo omni elytrisque 
flavo-marginatis, antennis pedibusque rufis, tarsis posterioribus picescentibus; pro- 
sterni processu lato, haud elongato; coxarum processubus apicibus breviter prolon- 
gatis, angustatis et acuminatis. Long. 32, lat. 16 m.m. 
Mas, nitidus, elytris ad apicem parum punctatis. 
